The RIAA is often referred to as if it were a single entity acting independently, but that's not quite the case. Its a trade organization that represents the interests of its members -- primarily the major record labels. And the major labels (Warner, Sony/BMG, EMI, Universal) are themselves conglomerates of several smaller labels that were either purchased or created along the way.
This layering has, in my opinion, helped insulate the labels from the consequences of their actions. The RIAA does what it does because that's what it's members want it to do. If you're upset about the RIAA's tactics and want to send a message by boycotting, go ahead. But there's no RIAA label for you not to buy.
Some savvy folks understand that its the member labels that drive the RIAA's actions, and take appropriate action. You may choose not to buy any record from the Universal Music Group, for example, but do you know enough to also pass on releases by Lost Highway Records, Geffen and Verve?
To help sort things out, there's the RIAA Radar. Simply enter an album, artist or label and it will tell you if the release(s) are by an RIAA member. The purpose of this post isn't a call to action, just a call to informed decision-making. Check the radar out and enter a few things. You might be surprised at what you find.
If the RIAA is the forest, then the majors are groves made up of stands of individual trees. So what are you seeing -- forest, grove, or tree?